index.css

* {
    font-family: 'Niramit', sans-serif;
    text-align: left;
    font-size: 16px;
}

.button {
    border: none;
    color: white;
    padding: 10px 20px;
    text-align: center;
    text-decoration: none;
    font-size: 16px;
    display: inline-block;
    background-color: lightseagreen;
    margin-top: 20px;
    cursor: pointer;
}

.button:disabled {
    background-color: darkgray;
    cursor: default;
}

.bold {
    font-size: 20px;
}

.text {
    resize: both;
}


/* 
 * Following code from w3schoools..
 * The container */
.container {
    display: block;
    position: relative;
    padding-left: 35px;
    margin-bottom: 12px;
    cursor: pointer;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* Hide the browser's default checkbox */
.container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

/* Create a custom checkbox */
.checkmark {
    position: absolute;
    top: 0;
    left: 0;
    height: 25px;
    width: 25px;
    background-color: #eee;
}

/* On mouse-over, add a grey background color */
.container:hover input ~ .checkmark {
    background-color: #ccc;
}

/* When the checkbox is checked, add a blue background */
.container input:checked ~ .checkmark {
    background-color: #2196F3;
}

/* Create the checkmark/indicator (hidden when not checked) */
.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

/* Show the checkmark when checked */
.container input:checked ~ .checkmark:after {
    display: block;
}

/* Style the checkmark/indicator */
.container .checkmark:after {
    left: 9px;
    top: 5px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 3px 3px 0;
    -webkit-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    transform: rotate(45deg);
}